The Research Of Rooting Mechanism In Three Species Of Eurya Cuttings

The paper selected Eurya japonica Thunb, Eurya muricata Dunn and Eurya nitida Korthals as materials and studied on mechanism of cutting propagation of them.The main results were as follows:1. Studied on cuttings techniques: The highest rooting percentage in spring was obtained from cuttings treated with IBA 1000mg/L of E. muricata, IBA 2000mg/L of E. nitida and NAA 1000mg/L of E. japonica respectively. The cuttings of E. japonica had the highest rooting rate in June 22, E. muricata and E. nitida respectively in May 17. The rooting rate of cuttings in spring and autumn without leaves and sprouts is zero. In spring, the rooting rate of cuttings with sprouts but without leaves is 23.33%. In autumn, the rooting rate of cuttings with sprout but without leaves is zero, while the rooting rate of cuttings without sprouts but with leaves is 14.44%. The time of leaf retention longer the rooting rate higher. The cuttings of E. japonica with 2 leaves in spring and 3 leaves in fall had the highest rooting rate.2. Cytology during adventitious rooting formation: The root primordium of E. japonica belonged to induced primoridum, which was orginated from the vascular cambium cell touching with the pith ray. The starch grains accumulated in the cells of cotex before root primodium initiation, later become fewer and fewer. The starch grains in periphery cells of root primodium almost disappeared or became smaller. The further away root primodium, the fewer changed of starch grains content.3. Studied on the physiology during adventitious root formation: The higher levels of IAA was demanded for root primodium induction and the development of adventitious root, and enogenous IAA, ABA, GA₃ plaied synerglstic action during cutting rooting. The content of starch and soluble sugar in the base of cuttings and leaves decreased markedly during cottage. Compared to the control, the content of starch in cuttings reduced, and the content soluble sugar in the base of cuttings increased, while the content soluble sugar in leaves decreased during cuttage. The POD might take part in the process of root primodiurn indcution and the roots expression. The activities of SOD, the content of ASA and GSH increased gradually during the root primodium induction and initiation, exogenous phytohormone could keep them in the higher levels in the long time. The content of water in cuttings, which was essential to all of physiological activity, related with cuttings rooting. The soluble protein and nucleic acid might take part in the process of adventitious root morphogenesis. The content of soluble protenin, Chla, Chlb and total Chl declined gradually in leaves, which exhibited senescence to a certain extent. Leaves senescene could be alleviatiated by using exogenous phytohormone, which enabled the leaves keeping activite physiological state consequently in favor of rooting.